Tamper Assembly

ABSTRACT

A tamper assembly comprising: a motor being coupled to a transfer shaft, rotating the transfer shaft when the motor is actuated. At least two eccentric weights are coupled to the transfer shaft and a tamping foot is rotatably coupled to the transfer shaft. The tamping foot vibrates when said motor is actuated to tamp the asphalt or the stone when the tamping foot is drawn across the asphalt or the stone behind an asphalt paver. Two attachment bars facilitate removable and adjustable attachment of the tamper assembly to an asphalt paver.

CROSS REFERENCE TO RELATED APPLICATIONS AND PRIORITY CLAIM

This application claims the benefit of provisional patent applicationU.S. Ser. No. 61/058,635 entitled “Tamper Assembly” filed by KevinPikuet on Jun. 4, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to vibrating tampers and more particularlypertains to a new tamper assembly that is removably attached to anasphalt paver, bulldozer, cold patch truck or other equipment fortamping stone, dirt or the edges of asphalt.

2. Description of the Prior Art

The lifetime (e.g. durability) of asphalt road surfaces can be greatlyenhanced by construction equipment and techniques that create tighterseals at asphalt seams. Tighter seals translate to a significantreduction in time, cost and resources used for road maintenance over theuseful lifetime of the asphalt road surface. Various vibrating tampersused in the construction, earth moving and asphalt paving industries areknown in the prior art and are used to create tighter asphalt seals.

As will be known to those skilled in the art, road paving is commonlyaccomplished by sequentially spreading, raking and rolling a top coat ofasphalt along a prepared surface of crusher stone, base, bindermaterial, and the like. A typical road width generally exceeds the widtha typical roller, thus requiring several passes of the asphalt paver androller to complete a particular asphalt road section. Seams are createdbetween the various rolled sections and form a weak point in the surfacethat is particularly susceptible to deterioration. When waterinfiltrates into the asphalt at these seams, the pooled water in theseams freezes and expands during cold weather, disrupting and dislodgingsurrounding asphalt. This results in cracking and potholes.

Another common source of asphalt road deterioration is the nonuniformdistribution of coarser particles across the peripheral surface of theasphalt material during the paving process. When the asphalt material islaid, the screed or wing of the asphalt paver causes these coarserparticles to flow toward the outer edge of the asphalt material beinglaid. Over time, this aggregation of many coarser particles along theouter edge results in dislodging of these coarser particles; creatingcracking, potholes and general road deterioration at the road edges.Thus, it is desirable to provide a device or assembly that prevents anouter edge aggregation of coarser asphalt particles during the pavingprocess.

To create tight seams (that prevent the infiltration of water at theseams), various techniques have been used in the prior art. The mostcommon technique is rolling (e.g. compacting) the seams. This rolling orcompacting process may be enhanced with the application of heat and/orfluids to bring the asphalt to an optimum consistency and/or temperaturefor compacting. However, this process has well known drawbacks. In theprior art, an asphalt paver first lays the asphalt at a temperature thatis optimal for spreading and compaction. Then, in a second process, aroller is applied to the asphalt for compaction. The independent rollerequipment follows the asphalt paver at a distance of about 400-1600 feet(487.7 meters), generally around 500 feet (152.4 meters), exposing theasphalt surface to the environment for a period of time and cooling theasphalt material. Thus, when the roller compacts the asphalt material,the asphalt material has already cooled to a temperature below theoptimal range required for the greatest compaction. Thus, the compactionand seal are not ideal, that is, not as tight as possible and havingexcessive voids disposed throughout.

To facilitate a more uniform distribution of coarser particles along theperipheral surface of the asphalt material, various techniques have beenused in the prior art. The most common technique involves a workerstanding at the side of the seam manually sweeping the coarser particlesback toward the center of the asphalt surface with a broom or rake. Theworker brushes off the excess at the seam and pushes the excess towardthe mat “hot pass” section such that the fines remain at the edge andthe coarser rocks and particles are spread inwardly toward the mat wherethey compacted into the surface. This is a labor intensive and costlysolution that produces inconsistent results.

Prior art attempts to propose a solution for these known limitations anddrawbacks in the prior art include an adjustable shoe such as theCedarapids Company model 361 or 362 asphalt paver that enables thescreed to lay correct the amount of asphalt and keep the asphalt inplace. However, these devices are known to cause sharp edges,inconsistent surfaces and pocks. Additionally, this equipment causesfriction and drag on the asphalt paver.

The inventor invented a tamping device disclosed in U.S. Pat. No.7,316,524. However, this portable hand held tamper is not suited tolarge asphalt paving and road construction projects. The presentinvention improves upon this technology by providing an assemblyconfigured for attachment to a vehicle and capable of utilizing thehydraulics and fuel supply already available on the vehicle.

While these devices fulfill their respective, particular objectives andrequirements, the need remains for a device or an assembly that isremovably and adjustably affixed to an asphalt paver (or otherequipment) that comprises a tamper having off centered weights that arerotated to create the vibration. While some of the prior art deviceshave gained popularity, they have not been successful in creating thenecessary compaction to eliminate or minimize water infiltration at theseams. They have also not been successful in uniformly distributing theasphalt particles across the asphalt surface to eliminate or minimizeaggregation of these coarser particles at the outer edges. They alsohave not been successful in applying the compacting forces while theasphalt is at optimal temperature ranges.

It is desirable to design a device or assembly that is compatible withthe prior art asphalt paving and compacting devices, improving upontheir functionality and eliminating one or more of their limitations.The present invention fulfills this need and others.

SUMMARY OF THE INVENTION

The present invention meets the needs presented above by generallycomprising a tamper assembly for tamping asphalt or stone placed on asurface, said assembly comprising: a motor being coupled to a transfershaft, said motor rotating said transfer shaft when said motor isactuated; a plurality of eccentric weights being coupled to saidtransfer shaft; a first attachment bar being rotatably coupled (via aball joint) to a mounting bracket at a proximal end and a ball joint ona first support on a distal end of said first attachment bar; a secondattachment bar being rotatably coupled (via a ball joint) to saidmounting bracket at a proximal end and a ball joint of a second supporton a distal end of said second attachment bar; said first attachment barand said second attachment bar being adjustable with respect to saidtamping foot via ball joints; said mounting bracket being configured forremovable attachment to an asphalt paver; said first support and saidsecond support being coupled to said tamping foot via ball joints; and atamping foot being rotatably coupled to said transfer shaft, saidtamping foot vibrating when said motor is actuated to tamp the asphaltor the stone and said tamping foot is drawn across the asphalt or thestone.

In one preferred embodiment, the device or assembly incorporates aliquid supply assembly to supply liquid to the screed prior to tampingto inhibit the tamper components from sticking to the asphalt. Inanother preferred embodiment, the device or assembly incorporates a heatsource to apply heat to the asphalt surface, thereby increasing thetemperature of the asphalt material, prior to tamping. In anotherpreferred embodiment, the assembly or device incorporates a rake todistribute the asphalt particles in a manner that prevents theaggregation of coarser particles along the outer edge during the pavingprocess.

It is an object of the present invention to provide a tamper assemblythat is removably attached to an asphalt paver, bulldozer, cold patchtruck or other equipment for tamping stone, dirt or the edges ofasphalt.

It is an object of the present invention to provide an assembly thatrakes off excess seam material or high spots prior to compaction.

It is an object of the present invention to provide an assembly thatsupplies liquid to the screed prior to tamping to inhibit the tampercomponents from sticking to the asphalt.

It is an object of the present invention to provide an assembly thatapplies heat to the asphalt surface, thereby increasing the temperatureof the asphalt material, prior to tamping.

It is an object of the present invention to provide an assembly thatdistributes the asphalt particles in a manner that prevents theaggregation of coarser particles along the outer edge during the pavingprocess.

It is a further object of the present invention to provide an assemblythat preheats seam material prior to compacting and sealing the seam.

It is a further object of the present invention to provide an assemblythat seals an asphalt seam at proper temperature.

It is a further object of the present invention to provide an assemblythat seals an asphalt seam through the vibration of eccentric weights.

It is a further object of the present invention to provide an assemblythat creates a smoothing effect across a seam during the seam sealingprocess.

Whereas there may be many embodiments of the present invention, eachembodiment may meet one or more of the foregoing recited objects in anycombination. It is not intended that each embodiment will necessarilymeet each objective.

Thus, having broadly outlined the more important features of the presentinvention in order that the detailed description thereof may be betterunderstood, and that the present contribution to the art may be betterappreciated, there are, of course, additional features of the presentinvention that will be described herein and will form a part of thesubject matter of the claims appended to this specification.

In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and thearrangements of the components set forth in the following description orillustrated in the drawings. The present invention is capable of otherembodiments and of being practiced and carried out in various ways. Alsoit is to be understood that the phraseology and terminology employedherein are for the purpose of description and should not be regarded aslimiting.

PARTICULAR ADVANTAGES OF THE INVENTION

The novel tamping assembly disclosed herein may be used withconventional equipment, and in particular, with an asphalt paver, tooptimize the conditions for asphalt paving and improve the final asphaltproduct. The assembly automates labor intensive manual functions,offering a significant labor savings.

By preventing an outer edge aggregation of coarser asphalt particles,there is a more uniform distribution of coarser particles across theperipheral surface of the asphalt material laid by the paver, andespecially in the “hot pass” portion. Uniformly distributing the asphaltparticles across the asphalt surface eliminates or minimizes aggregationof coarser particles at the outer edges.

By minimizing the time exposure of the asphalt surface to cooling, theroller compacts the asphalt material at temperatures required for thegreatest compaction. This creates the necessary compaction to minimize,or even eliminate, voids in the compacted asphalt, and thus, minimizingor eliminating water infiltration at the seams.

This tamping assembly is mounted behind the paver, eliminating thefriction and drag “skis” typically have on the asphalt paver. It isremovable and adjustable, offering great flexibility to the user.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objects other than those setforth above will become apparent when consideration is given to thefollowing detailed description thereof. Such description makes referenceto the annexed drawings, in which like numerals refer to like elements,and wherein:

FIG. 1 is a perspective view of a tamper assembly of the presentinvention;

FIG. 2 is perspective view of the tamper assembly of FIG. 1 as mountedfor use on an asphalt paver;

FIG. 3 is a top plan view of the tamper assembly of FIG. 1;

FIG. 4 is a right side elevational view of the tamper assembly of FIG.1;

FIG. 5 is a front elevational view of the tamper assembly of FIG. 1;

FIG. 6 is a detailed close-up view of a pitch adjusting mechanism of thetamper assembly of FIG. 1;

FIG. 7 is a cross section taken along A-A of FIG. 3; and

FIG. 8 is a top plan view of the tamper assembly of FIG. 1 as mountedfor use on an asphalt paver.

The drawings are not to scale, in fact, some aspects have beenemphasized for a better illustration and understanding of the writtendescription.

PARTS LIST

-   2 tamper assembly-   3 screed-   4 turnbuckle-   5 deck-   6 bars-   8 mounting bracket-   10 edge-   12 seam-   13 screed unit-   14 vehicle-   15 screed extension-   16 tamping foot-   18 support-   20 support-   22 ball joint-   24 Ball joint-   26 cutouts-   28 lute-   30 positions-   32 nose-   36 adjustment screw-   38 adjusting mechanism-   40 bolt-   42 width-   44 distance-   46 length-   48 distance-   50 length-   52 distance-   54 distance-   56 distance-   58 angle-   60 distance-   62 A-frame bracket-   64 eccentric weights-   66 eccentric weights-   68 bearing-   70 shaft-   72 coupler-   74 motor-   75 fuel hose-   76 mounting support-   77 hydraulic line-   78 manifold-   80 peripheral edge-   82 shape-   84 fuel line-   86 lubricant sprayer-   88 flame burner system-   90 height-   92 height-   93 distance-   94 distance-   96 distance-   98 ball joint assemblies-   100 ball joint assemblies-   102 pitch-   104 surface-   106 height-   108 fastener-   112 direction-   114 distance-   116 distance-   118 edge-   120 pass-   122 pass

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

FIG. 1 depicts one embodiment of a tamper assembly 2 of the presentinvention. FIG. 2 is a perspective view of the tamper assembly of FIG. 1as mounted for use on an asphalt paver. FIG. 3 is a top plan view of thetamper assembly of FIG. 1. FIG. 4 is a right side elevational view ofthe tamper assembly of FIG. 1.

Referring to FIGS. 1-4, the tamper assembly 2 comprises a motor 74 beingcoupled to coupler 72 that is coupled to a transfer shaft 70, rotatingthe transfer shaft 70 when the motor 74 is actuated. At least twoeccentric weights 64, 68 are coupled to the transfer shaft 70 and atamping foot 16 is rotatably coupled to the transfer shaft 70. Each ofthe eccentric weights 64, 66 is positioned off center to vibrate thetamping foot 16 when the transfer shaft 70 is rotated. The tamping foot16 vibrates when the motor 74 is actuated to tamp the asphalt or thestone when the tamping foot 16 is drawn across the asphalt or the stonebehind a vehicle 14 such as an asphalt paver. Tamping foot 16 comprisesa screed 3 that contacts the asphalt and a deck 5 that houses orprovides a mounting surface for many of the functional elements of thetamper assembly (e.g., motor, transfer shaft, etc.). The deck 5 andscreed 3 may be integrally formed or formed as two separate componentsand affixed to one another to form tamping foot 16.

Referring to FIG. 1, the tamper assembly 2 is configured to be removablyand adjustably attached to a vehicle 14 via the mounting unit (see FIG.2 for illustration). As used in this specification, a vehicle 14includes an asphalt paver, bulldozer, cold patch truck or otherequipment for tamping stone, dirt or the edges of asphalt. In theembodiment depicted, the mounting unit is formed of mounting bracket 8,two attachment bars 6, 6A each having an adjustable turnbuckle 4, 4A,and fastening hardware. The mounting unit facilitates removable andadjustable attachment of the tamper assembly 2 to a vehicle 14. Thissimple means of attaching and adjusting the tamper assembly 2 to avehicle via two simple bars 6, 6A with turnbuckles 4, 4A in the centerand ball joints at both opposing ends is an important feature of theembodiment of the present invention depicted in FIGS. 1-8.

It is to be understood that the mounting unit illustrated in theembodiment depicted in FIGS. 1-8 is merely illustrative and not intendedto be limiting in scope. Other mounting units, especially other mountingbrackets and fastening hardware (e.g. a screw, bolt, clamp, mechanicalfastener or nonmechanical fastening mechanism) and/or adjustable lengthattachment bars may be suitably adapted for use with the presentinvention. Preferably, the mounting unit is configured such that tamperassembly 2 is disposed a short distance behind the vehicle 14. Theshorter the distance, the less heat loss from the newly laid asphalt andthe greater the compaction of the asphalt at the seam 12.

The mounting points of the tamper assembly 2 to the asphalt paver 14 arecontrolled by the tamping foot 16, the length of the attachment bars 6,6A and the location of the edge of the seal 12 being pinched.Preferably, as depicted in FIG. 2, one mounting point is flush on theedge 118 of the asphalt paver 14 and the other mounting point is aboutthe rear of the screed unit 13 over the mat of the newly laid asphalt.

In an alternative embodiment (not depicted), mounting is in the rearcenter of the screed unit 13. This central position allows the tamperassembly 2 to be disposed over seams 12 to the right or left of theasphalt paver 14 without having to remount the entire tamper assembly 2.

Referring to FIG. 3, a first attachment bar 6 is rotatably coupled (viaa ball joint) to a mounting bracket at its proximal end and a ball jointof a first support on its distal end. A second attachment bar 6A isrotatably coupled (via a ball joint) to the mounting bracket at itsproximal end and a ball joint of a second support on its distal end.Both the first attachment bar 6 and said second attachment bar 6A arethus adjustable with respect to the tamping foot 16. The first supportand second support are coupled to the tamping foot 16.

As depicted in FIGS. 1-8, the tamper assembly 2 incorporates a hydraulicmotor 74 being coupled to coupler 72 in turn coupled to a transfer shaft70. The transfer shaft 70 extends along at least a portion of the lengthof the tamping foot 16. The tamping foot 16, and in particular, thescreed 3 thereof, abuts and vibrates against asphalt or stone to tampthe asphalt or the stone when the transfer shaft 70 and the eccentricweights 64, 66 are rotated.

In use, the hydraulic motor 74 is actuated to rotate the transfer shaft70. As the transfer shaft 70 is rotated the transfer shaft 70 is rotatedwhich rotates eccentric weights 64 and 66. The off center orientation ofthe eccentric weights 64, 66 creates a vibration in the tamping foot 16and vibrates the tamping foot 16 which is positioned against the asphaltor the stone. The vibration of the tamping foot 16 tamps the asphalt orstone.

Referring to FIG. 4, a hydraulic line 77 feeds hydraulic fluid to ahydraulic system of a hydraulic motor 74 coupled to the tamping foot 16by mounting support 76. A hydraulic fluid return line is also provided.A hydraulic fluid supply assembly includes a hydraulic fluid supply tankdisposed on the asphalt paver 14 that stores the hydraulic fluid to betransported through the hydraulic line to the hydraulic motor 74 whenone or more valves (not depicted) are actuated. As will be apparent tothose skilled in the art, many configurations of hydraulic motor systemsmay suitably be incorporated in the present invention. A hydraulic fluidsupply system and tank similar to the fluid supply system for fuel oildescribed below may also be provided.

Incorporation of the hydraulics and fuel supply available on the vehicle14 allows the tamping assembly to be lighter in weight and mechanicallyless complex. By way of example, an apparatus that used mechanicallinkages to power the eccentric weights would require more complexlinkages and gears, requiring more physical space and preventing thecompact profile and footprint of the present invention. This may causeobstructions with existing component parts (e.g. screed 13) of thevehicle 14 and make a universally attachable assembly 2 difficult toconfigure. The present invention addresses these limitations andprovides a solution that is highly adaptable and easy to manufacture.

Coupler 72 transfers the power from the hydraulic motor 74 to thetransfer shaft 70. Eccentric weights 64 and 66 are mounted abouttransfer shaft 70 and create the vibration of the tamper assembly 2.A-frame bracket 62 couples attachment bar 6 to the tamping foot 16 viaball joint 22. Two pillow block bearings 68 (one hidden from view behindA-frame bracket 62 but see FIG. 1) support the transfer shaft 70.

Ball joint 24 couples a second attachment bar 6A to support 18, 20disposed on the tamping foot 16. One support 18, 20 is disposed oneither side of the tamping foot 16 to facilitate mounting of the tamperassembly 2 along a seam on both the right and left sides of the asphaltpaver 14. The axis of each ball joint 22, 24 is perpendicular withrespect to the other and the centerpoints of ball joints 22, 24 aredisposed at a distance 60 from one another of from about 8 inches (about20.32 centimeters) to about 10 inches (about 25.4 centimeters) from oneanother. The centerpoint of ball joint 22 is disposed at a distance 48from the rear peripheral edge of the tamping foot 16 and a distance 44from the both side peripheral edges of the tamping foot 16. A similarconfiguration is provided for support 20 on the right side of thetamping assembly 2.

Turnbuckle 4, 4A and attachment bar 6, 6A adjustably position the tamperassembly 2 about the asphalt surface (or ground, soil, sand, clay,stone, etc.). Preferably, and as illustrated and discussed more fullywith respect to FIG. 8, the tamper assembly 2 is disposed about the edge10 of a screed 13 such that it 2 traverses an asphalt seam 12. Whenused, compaction and a smoothing effect are caused by friction,vibration and the weight of the tamper assembly 2 as it traverses acrossthe asphalt seam 12.

Compaction by an asphalt paver 14 generally ranges from about 80 percent(either vibrating plate or vibrating tamper bar) to about 92 percent(both vibrating plate or vibrating tamper bar). The final compactionlayer is generally performed by rollers (steel or tire). The finaldensity of the asphalt has a huge effect on the mechanical properties ofthe asphalt, especially on resistance against permanent deformation.Thus, compaction is a critical process for ensuring long term durabilityof the road. Compaction aims to reduce volume and increase density. Poorcompaction during construction results in post compaction by vehiclestraveling over the road and unevenness in the road surface over time.Asphalt compaction is greatest with a combination of static compaction(e.g. with a road roller) and vibratory compaction (e.g. with avibrating tamper). The tamper assembly 2 provides vibratory compactionthat may be followed by static compaction via a roller.

Compaction is optimum when the asphalt temperature is sufficiently highbecause the viscosity of the bitumen is sufficiently low. Compaction isseverely impeded at temperatures below 70 degrees Celsius (158 degreeFahrenheit). Proper compaction of seams requires both preventing loss ofheat from the newly laid asphalt from the hot pass and preheating thepreviously laid asphalt on the cold pass and/or underlayer. The tamperassembly 2 provides a device that does both, offering the best possibleseam and mat compaction results. Preventing loss of heat from the newlylaid asphalt is accomplished by the close proximity of the tamper unitto the vehicle 14, thereby minimizing heat loss from exposure to ambientair. Preheating the previously laid asphalt on the cold pass isaccomplished by the flame burner system 88 (flame throwers). The flameburner system 88 (flame throwers) also provide a means of heating theunderlayer to enhance adhesion or newly laid asphalt should heat losshave occurred.

Maintaining proper asphalt temperature is important to the overallresults of an asphalt paving project. During the precompaction by theasphalt paver 14, the asphalt material still has a very high temperatureand can thus be compacted easily. The asphalt material is preferably inthe range of from about 130 to about 150 degrees Celsius (about 266 toabout 302 degree Fahrenheit) when it enters the hopper. Preferably thenewly laid asphalt material has not cooled more than about 5 degreesCelsius (about 41 degree Fahrenheit) after precompaction by the screedunit 13. Preferably, the temperature of the asphalt during compaction bythe tamper assembly 2 is from about 250 to about 290 degrees Fahrenheit(about 121.1 to about 143.3 degree Celsius) when the seam is sealed.Pinching the seams at these temperatures increases the life expectancyof the asphalt road by as much as 50%.

Laying an asphalt road requires several steps: transporting thepremanufactured asphalt mixture to the work site by truck, laying andprofiling the asphalt material with an asphalt paver 14, compacting theasphalt and final treatment of the surface. Compacting generally has twocomponents: precompacting by the screed 13 of the asphalt paver 14 andcompacting by a static compactor or vibratory compactor. Seams aregenerally compacted with two rollers: one on the old “cold” pass and oneon the new “hot” pass. Preferably, these rollers work together to pushasphalt toward the center as the seams are pinched.

As will be demonstrated, the tamper assembly 2 functions to “pinch” theseam by vibratory compaction as it travels behind the asphalt paver 14.Thus, one roller (the roller on the cold side) can be dispensed with ina typical paving operation. As such, the paving process is moreeconomical and efficient—one less machine, less fuel for operation, andone less machine operator required in the paving process. In somecontexts, additional economies are realized when additional workers(such as wingmen and/or manual rakers) are dispensed with. Applicantestimates that savings range from about 10% to about 30% for a givenjob, with 15% being the average savings for a typical job.

Referring to FIG. 2, the tamper assembly 2 is removably attached to therear of an asphalt paver 14, preferably to the screed unit 13. In oneembodiment, the tamper assembly 2 is mounted on the screed extension 15.It may also be mounted to the screed plate, tamper bar, wing assembly orother portion of the screed.

Referring to FIG. 2, asphalt pavers 14 are mechanically driven spreadingand profiling machines on tracks or rubber tires. Asphalt pavers 14generally contain a hopper for the asphalt material, a spreading unitand a compaction unit. Asphalt is dumped into the hopper by trucks andtransported to the rear side of the asphalt spreader by horizontalconveyor belts. The asphalt is spread over the required width by screwsor augers.

A screed unit 13 is attached to the rear of the asphalt paver 14 andgenerally contains a vertically vibrating tamper bar and/or a widevibrating plate, leveling arms 15 and a screed plate. The screed unit 13initially compacts the asphalt to create an asphalt layer with a uniformthickness. The vibrating plate or vibrating tamper bar generallycontains a heating system. The width of the screed unit 13 (so thespreading width of the asphalt) generally varies from about 2 to about12 meters (about 6.562 to about 39.37 feet). Adding or removingextension pieces or built-in hydraulic extensions can extend the widthby an additional 20 feet (6.096 meters) or more. The height of thescreed unit 13 is generally controlled by a conducting wire at bothsides of the road under construction (typical for asphalt base andbinder layers), a ski or a shoe connected to the asphalt paver and fromwhich the height level is imported by the asphalt paver (typical forupper asphalt layer). Thus, as will be discussed in greater detailbelow, it is important that the size, profile and mounting position ofthe tamping assembly 2 be configured to avoid interference with thesetypical pieces/components of equipment, thus creating the most universalrange of equipment upon which this aftermarket accessory 2 can beremovably attached.

Referring to FIGS. 3 and 4, the tamping foot 16 has a small footprint,having a width 42 of from about 8 to about 12 inches (about 20.32 toabout 30.48 centimeters) and a length 46 of from about 25 to about 48inches (about 63.5 to about 121.9 centimeters) as measured from the rearperipheral edge to the leading edge of the lute. In a preferredembodiment, the length 46 is no more than about 36 inches (about 91.44centimeters). The tamping foot's 16 profile is similarly compact andportable as compared with similarly functioning road constructionequipment, having a height 92 of from about 12 inches (about 30.48centimeters) to about 18 inches (about 45.72 centimeters). The eccentricweights and attachment bar of the tamper assembly 2 add addition height90 of from about 12 inches (about 30.48 centimeters) to about 18 inches(about 45.72 centimeters).

It is to be understood that a separate tamper assembly unit is notessential, but that the various components and functions of the tamperassembly can also be incorporated in other pieces of equipment. Suchembodiments are considered within the scope of the present invention.

Referring to FIG. 3, a lute 28, also known as a lute rake or squeegee,brushes off high standing asphalt material along the peripheral surfacewith a blade, enabling the tamping plate or skis to contact asubstantially flush surface and properly compact the asphalt material.This vibratory compaction pinches the seam, creating a tight, smoothseal and high density asphalt. The lute 28 has a length 50 of from about8 to about 12 inches (about 20.32 to about 30.48 centimeters) and isadjustable to variable positions 30 in use as necessary to direct thehigh standing excess material in the desired direction, preferablytoward the mat. Adjustment screw 36 allows the lute angle to be manuallyadjusted.

Referring to FIG. 3, the contour of the tamping foot 16 nose 32 isangled inwardly toward the center at an angle 58 of from about 0 degreesto about 45 degrees to allow the lute a greater range of motion.

Referring to FIG. 4, a liquid supply from the asphalt paver passesthrough fuel hose 75 into manifold 78 which is coupled to the tampingfoot 16 and fuel line 84. The fuel line 84 supplies the burner system 88(also known as a flame thrower) and in some embodiments, also suppliesthe lubricant sprayer 86 which dispenses a mist or stream of lubricantliquid on the screed. Any fuel may be used, but petroleum based productssuch as kerosene and diesel are most commonly and preferably used in thepaving industry. Additionally, the use of petroleum based fuel allowsthe fuel to also serve as the lubricant (described in greater detailbelow).

In an alternative embodiment (not depicted), a supply tank stores theliquid. In one embodiment, two or more supply tanks are coupled to thetamping foot 16. In one embodiment with two supply tanks, fuel andlubricant are stored in each tank respectively. As will be apparent,substantially similar or duplicate liquid supply systems may be providedfor embodiments with multiple supply tanks.

A valve (not depicted) is coupled to each spray nozzle 86 and burnersystem 88 (flame thrower) and in fluid communication with the supply.The valves control a flow of the fluid from the supply when the valvesare actuated. In the embodiment depicted, there are at least fourvalves.

When activated, the burner system 88 (flame thrower) applies heat to thecooled asphalt prior to coming into contact with the tamper assembly 2.The cooled asphalt material, commonly known as spam, is thus preheatedprior to compaction. This preheating process brings the asphalt materialto an optimum temperature range for maximum compaction and adhesion.Preferably, the burner system 88 heats the spam to a temperature of fromabout 100 degrees Fahrenheit (about 37.78 degree Celsius) to about 300degrees Fahrenheit (about 148.9 degree Celsius), preferably from about100 degrees Fahrenheit (about 37.78 degree Celsius) to about 150 degreesFahrenheit (about 65.56 degree Celsius). As will be known to thoseskilled in the art, the desired temperature is dependent upon a numberof factors, including ambient air temperature, ground temperature, andthe like. The cooler the ambient or ground temperature, the greater thedesired temperature increase in the spam to bring it to a pliableconsistency for compacting and sealing. Preferably, the asphalt, an inparticular, a prior seam 12 of a cold pass or underlayer, is heated bythe burner system 88 (flame throwers) to a point when the asphalttransforms to a glossy black color, indicating that the tar issufficiently loose enough to allow for proper compaction and adhesion.Adhesion of the newly laid asphalt is enhanced when the tar of theunderlayer (e.g., first pass, base or binder) to which it is applied issufficiently loose and pliable.

When activated, a lubricant sprayer 86 sprays a light coating or film oflubricant (e.g. fuel oil) on and in front of the base of the tampingfoot 16 and/or screed 3 prior to coming into contact with the tamperassembly 2. This lubricant prevents the bottom of the tamper assembly 2from sticking to the heated asphalt material and causing sheering of thenewly laid asphalt. This is most often used during the early stages of apaving operation during a given time period before the screed heats upto a temperature sufficient to preventing sticking.

A lubricant sprayer 86 is coupled to the fuel line 84 of the tampingfoot 16 and extends around a perimeter of the tamping foot 16. Thelubricant sprayer 86 is in fluid communication with the valve (notdepicted). The lubricant sprayer 86 sprays the liquid onto the screedand/or asphalt around the tamping foot 16 when the valve is actuated toallow the liquid to flow from the supply.

Referring to FIG. 4, the tips of the flame burner system 88 (flamethrower) are preferably disposed a distance 96 of from about 2 inches(about 5.08 centimeters) to about 6 inches (about 15.24 centimeters),preferably from about 2 inches (about 5.08 centimeters) to about 4inches (about 10.16 centimeters), from the bottom of the tamper assembly2 and accordingly, from the surface of the asphalt. Preferably, thelubricant sprayers 86 are disposed a distance 94 of from about 1 toabout 8 inches (about 2.54 to about 20.32 centimeters), preferably fromabout 3 inches (about 7.62 centimeters) to about 4 inches (about 10.16centimeters), from the bottom of the tamper assembly 2 and accordingly,from the surface of the asphalt. In another embodiment (not depicted),the lubricant sprayers 86 are disposed on the deck 5 of the tamper foot16. Preferably, the lubricant sprayers 86 are not disposed higher thanthe deck 5 of the tamper foot 16.

Referring to the embodiment depicted in FIGS. 3 and 4, lubricantsprayers 86 are preferably disposed a distance 54 of from about 2 inches(about 5.08 centimeters) to about 3 inches (about 7.62 centimeters) fromthe tips of the flame burner system 88 (flame thrower). The tips of theflame burner system 88 (flame thrower) are preferably disposed adistance 56 of from about 1 inch (about 2.54 centimeters) to about 2inches (about 5.08 centimeters) from the leading edge of the lute. Thesprayers 86 are preferably disposed a distance 56 of from about 3 toabout 6 inches (about 7.62 to about 15.24 centimeters) from the leadingedge of the lute.

Referring to FIG. 3, in the embodiment depicted, the tips of the flameburner system 88 (flame thrower) and the lubricant sprayers 86 aredisposed along two arms a distance 52 of from about three inches toabout four inches from one another. It is contemplated that otherconfigurations (and numbers of sprayers 86 and flame throwers 88) willbe used with and are considered within the scope of the presentinvention. In one aspect, the flame burner system 88 (flame thrower)and/or the lubricant sprayers 86 comprise adjustable nozzles.

The peripheral edge 80 of the screed 3 of the tamping foot 16 preferablyis chamfered or rounded along its exterior surface. It is formed with aslight curve or contour (also known as a “bull nose”) or rounded profilesuch that there are no sharp edges along the lower edges of the tampingfoot 16. The angle of the curve is not critical but can be selected toaccomplish the purpose of minimizing stress, absorbing shock andpreventing breakage at this juncture, in particular, that caused whenthe tamping foot 16 contacts the asphalt surface during use. Itpreferably has a natural 45 degree radius curve.

FIG. 5 is a front elevational view of the tamper assembly 2 of FIG. 1.FIG. 6 is a detailed close-up view of a portion (the pitch adjustingmechanism 38) of the tamper assembly 2 of FIG. 1.

Referring to FIGS. 3, 4, 5 and 6, when the lute approaches its in useposition and the angle with respect to the nose of the tamping foot 16is great enough, the lute contacts pitch adjusting mechanism 38 (affixedto the tamping foot 16 by bolt 40), raising one side of the lute fromthe surface of the asphalt, thereby creating a slight lute pitch (see102 of FIG. 5) of from about 0.01 to about 5 degrees along theperipheral surface of the asphalt when it is compacted. As used in thisspecification lute pitch means the angle created by the lute withrespect to the ground or asphalt surface. Bolt 40 allows play andflexibility of the pitch adjusting mechanism 38 with respect to thelute. It is to be appreciated that a ball joint may be suitably adaptedto this application 40. Adjusting mechanism's 38 contacting surface 104preferably is chamfered or rounded along its exterior surface. It isformed with a slight curve or contour such that it is gently forced overthe upper edge of the tamping foot 16 when it comes in contacttherewith.

Lute head has a cross sectional shape 82 comprising a complex convexirregular octagon and a height 106 of from about 4 inches (about 10.16centimeters) to about 6 inches (about 15.24 centimeters).

FIG. 7 is a cross section taken along A-A of FIG. 3 and FIG. 8 is a topplan view of the tamper assembly 2 of FIG. 1 as mounted for use on anasphalt paver 14. Referring again to FIG. 3 and also to FIG. 7, cutouts26 create material voids to reduce the weight of the tamping foot 16.

Referring to FIG. 7, eccentric weights 64 and 66 surround transfer shaft70 and are clamped in place via fastener 108. The mechanical fastener108 is a bolt or screw in the embodiment depicted. The eccentric weightscause vibration and provide the compacting function of the tamperassembly 2.

Referring to FIG. 8, ball joint assemblies 98,100 allow adjustablemovement of the attachment bars 6, 6A and couple them to the mountingbracket 8. The ball joints 98,100 are disposed a distance 116 apart offrom about 8 inches (about 20.32 centimeters) to about 16 inches (about40.64 centimeters) and a distance 114 of from about 1 inch (about 2.54centimeters) to about 8 inches (about 20.32 centimeters) from the side(as measured from the peripheral edge) of the mounting bracket 8.

During use, the tamper assembly 2 is preferably disposed over the seam12 such that about three fourths of the tamper assembly 2 contacts thecold pass 122 and one quarter contacts the hot pass 120. Put anotherway, the exterior of side 118 is disposed over the asphalt a distance ofabout 0.25 of the width 42 from seam 12 (thus from about 2 to about 3inches (about 5.08 to about 7.62 centimeters) from the seam 12). Thetamper assembly 2 is towed in the forward direction 112 behind theasphalt paver 14

The tamper assembly 2 may be configured for attachment to an asphaltpaver 14, a bulldozer, a cold patch truck, and the like. While it isanticipated that the tamper assembly 2 will most frequently be used onprojects with a single asphalt paver, it conceivably may be used withtandem passes with two asphalt pavers as well. It 2 may be configuredfor attachment to a wing extender, a screed extender or various othercomponent portions of the asphalt paving machine 14. It is importantthat the tamper assembly 2 be attached in a manner that does notinterfere with other component parts of the screed unit 13. Generally,other components of the screed unit 13 or attachments thereto aredisposed outwardly a distance of about 24 inches (about 60.96centimeters) (unless there is oncoming traffic or tandem paver units)and are never disposed over the seam. Thus, the compact profile andwidth 42 of the tamper assembly 2 allow it to easily be mounted suchthat is traverses over the seam without interference with operativeparts of the machinery.

The tamping foot 16 may be formed of one or more materials. The deck 5may be formed of casted aluminum or iron. The screed 3 may be made ofthe same casted aluminum or iron, or alternatively, be formed of hightensile steel, high strength aluminum or aluminum alloys, or titanium.Other materials known to those skilled in the art are suitably adaptedto the present invention.

The tamper assembly 2 may also be used in trenchwork (ditches) tocompact soil or stone after utility facilities or drainage pipe is laid.As will be apparent, the flame throwers and lubricant sprayers would notbe incorporated in this application.

With respect to the above description then, it is to be realized thatthe optimum dimensional relationships for the parts of the invention, toinclude variations in size, materials, shape, form, function and mannerof operation, assembly and use, are deemed readily apparent and obviousto one skilled in the art, and all equivalent relationships to thoseillustrated in the drawings and described in the specification areintended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of theprinciples of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, it is notdesired to limit the invention to the exact construction and operationshown and described, and accordingly, all suitable modifications andequivalents may be resorted to, falling within the scope of theinvention.

1. A tamper assembly for tamping asphalt or stone placed on a surface,said assembly comprising: a motor being coupled to a coupler coupled toa transfer shaft, said motor rotating said transfer shaft when saidmotor is actuated; a plurality of eccentric weights being coupled tosaid transfer shaft; a mounting unit configured for attachment to avehicle; and a tamping foot being rotatably coupled to said transfershaft, said tamping foot vibrating when said motor is actuated to tampthe asphalt or the stone when said tamping foot is drawn across theasphalt or the stone.
 2. The tamper assembly of claim 1 wherein thetamping foot comprises a screed for contacting the asphalt and whereinthe tamper assembly causes asphalt compaction and a smoothing effect byfriction of the screed of the tamper foot, vibration of the eccentricweights and a weight of the tamper assembly as it is drawn across theasphalt.
 3. The tamper assembly of claim 1 wherein the mounting unitcomprises a mounting bracket, two attachment bars each having anadjustable turnbuckle and rotatably coupled to a proximal end of themounting bracket such that the attachment bars are adjustable withrespect to the tamping foot.
 4. The tamper assembly of claim 3 whereinthe mounting unit facilitates mounting of the tamper assembly along anasphalt seam on both the right and left sides of an asphalt paver suchthat the tamping assembly pinches the asphalt seam by vibratorycompaction when the tamping foot is drawn across the asphalt seam. 5.The tamper assembly of claim 1 wherein the motor comprises a hydraulicmotor and the tamper assembly further comprises a hydraulic line thatfeeds hydraulic fluid to a hydraulic system of the hydraulic motor. 6.The tamper assembly of claim 1 wherein the tamping foot has a basehaving a front and a back, and wherein the tamper assembly furthercomprises a lubricant sprayer coupled to a fuel line and extendingaround a perimeter of the tamping foot wherein the lubricant sprayersprays a light coating of lubricant about the front of the base of thetamping foot.
 7. The tamper assembly of claim 1 wherein the tamperassembly has a front and a back and further comprises a flame burnersystem coupled to the front of the tamper assembly.
 8. The tamperassembly of claim 7 wherein the flame burner system comprises a valvecoupled to a spray nozzle and in fluid communication with a fuel supplyand the valve controls a flow of fuel from the fuel supply when thevalve is actuated.
 9. The tamper assembly of claim 7 wherein the flameburner system is configured to apply heat to the asphalt prior to cominginto contact with and being compacted by the tamper assembly, heatingthe asphalt to a temperature of from 100 degrees Fahrenheit (about 37.78degree Celsius) to 150 degrees Fahrenheit (about 65.56 degree Celsius).10. The tamper assembly of claim 1 wherein the tamper assembly has afront and a back and further comprises a lute rake coupled to the frontof the tamper assembly that brushes off high standing asphalt materialalong the peripheral surface of the asphalt.
 11. The tamper assembly ofclaim 2 wherein a peripheral edge of the screed of the tamping foot ischamfered along its exterior surface.
 12. The tamper assembly of claim11 wherein the peripheral edge has a 45 degree radius curve.
 13. Atamper assembly for tamping a surface, said assembly comprising: a motorbeing coupled to a coupler coupled to a transfer shaft, said motorrotating said transfer shaft when said motor is actuated; a plurality ofeccentric weights being coupled to said transfer shaft; a mounting unit;wherein a tamping foot being rotatably coupled to said transfer shaft,said tamping foot vibrating when said motor is actuated to tamp thesurface when said tamping foot is drawn across the surface; wherein thetamping foot comprises a screed for contacting the surface and whereinthe tamper assembly causes compaction of the surface; wherein themounting unit comprises a mounting bracket, two attachment bars eachhaving an adjustable turnbuckle and rotatably coupled to a proximal endof the mounting bracket such that the attachment bars are adjustablewith respect to the tamping foot; wherein the motor comprises ahydraulic motor and the tamper assembly further comprises a hydraulicline that feeds hydraulic fluid to a hydraulic system of the hydraulicmotor; wherein the tamping foot has a base having a front and a back,and wherein the tamper assembly further comprises a lubricant sprayercoupled to a fuel line and extending around a perimeter of the tampingfoot wherein the lubricant sprayer sprays a light coating of lubricantabout the front of the base of the tamping foot; wherein the tamperassembly has a front and a back and further comprises a flame burnersystem coupled to the front of the tamper; wherein the flame burnersystem comprises a valve coupled to a spray nozzle and in fluidcommunication with a fuel supply and the valve controls a flow of fuelfrom the fuel supply when the valve is actuated; and wherein the tamperassembly has a front and a back and further comprises a lute rakecoupled to the front of the tamper assembly.
 14. A tamper assembly fortamping asphalt or stone placed on a surface, said assembly comprising:a motor being coupled to a coupler coupled to a transfer shaft, saidmotor rotating said transfer shaft when said motor is actuated; aplurality of eccentric weights being coupled to said transfer shaft; amounting unit configured for attachment to a vehicle; and a tamping footbeing rotatably coupled to said transfer shaft, said tamping footvibrating when said motor is actuated to tamp the asphalt when saidtamping foot is drawn across the asphalt; wherein the tamper assemblyhas a front and a back and further comprises a lute rake coupled to thefront of the tamper assembly; and wherein the tamper assemblyfacilitates a uniform distribution of coarse particles across aperipheral surface of asphalt material laid by an asphalt paver, therebypreventing aggregation of coarse asphalt particles at an outer edge ofthe asphalt.
 15. The tamper assembly of claim 14 wherein the tamperassembly has a front and a back and further comprises a flame burnersystem coupled to the front of the tamper assembly and having a fuelline.
 16. The tamper assembly of claim 15 wherein the tamping foot has abase having a front and a back, and wherein the tamper assembly furthercomprises a lubricant sprayer coupled to the fuel line and extendingaround a perimeter of the tamping foot wherein the lubricant sprayersprays a light coating of lubricant about the front of the base of thetamping foot.
 17. The tamper assembly of claim 15 wherein the tamperassembly has a front and a back and further comprises a flame burnersystem coupled to the front of the tamper assembly for heatingpreviously laid underlayment or asphalt, thereby minimizing temperaturereduction of the asphalt prior to compaction.
 18. The tamper assembly ofclaim 16 wherein the mounting unit comprises a mounting bracket, twoattachment bars each having an adjustable turnbuckle and rotatablycoupled to a proximal end of the mounting bracket such that theattachment bars are adjustable with respect to the tamping foot.
 19. Thetamper assembly of claim 18 wherein the tamper assembly has a front anda back and further comprises a lute rake coupled to the front of thetamper assembly.
 20. A tamper assembly for tamping asphalt or stoneplaced on a surface, said assembly comprising: a front and a back; amotor being coupled to a coupler coupled to a transfer shaft, said motorrotating said transfer shaft when said motor is actuated; a plurality ofeccentric weights being coupled to said transfer shaft; a tamping footbeing rotatably coupled to said transfer shaft, said tamping footvibrating when said motor is actuated to tamp the asphalt when saidtamping foot is drawn across the asphalt, and wherein the tamperassembly further comprises a lubricant sprayer coupled to a fuel lineand extending around a perimeter of the tamping foot; a mounting unitconfigured for attachment to a rear of an asphalt paver wherein themounting unit comprises a mounting bracket, two attachment bars eachhaving an adjustable turnbuckle and rotatably coupled to a proximal endof the mounting bracket such that the attachment bars are adjustablewith respect to the tamping foot; a lute rake and a flame burner systemcoupled to the front of the tamper assembly; and wherein the tamperassembly facilitates a uniform distribution of coarse particles across aperipheral surface of asphalt material laid by an asphalt paver, therebypreventing aggregation of coarse asphalt particles at an outer edge ofthe asphalt.